Frightfully Keen
by San Antonio Rose
Summary: In which Gil and Agatha take an extended honeymoon, Zeetha invents a new act, Tarvek fails to be above it all, and Mechanicsburg accidentally gains a new industry. (AU, timestamp to "De Profundis")


Frightfully Keen  
By San Antonio Rose

The thrill of recharging the castle had mostly worn down to a pleasant contentment and Agatha was drowsing with her head on Gil's bare chest, one ear listening to his heartbeat and one ear listening to the rain on the roof of the tower where they'd—ah—landed, when he said, "Father's going to be livid about our doing that in the middle of a storm."

"When else would we do it?" she returned. "We didn't have time to wait for your ionization engines to get here."

He chuckled. "Still."

"Well, we shouldn't have to do it again." She paused. "It was fun, though."

"We should still find something safer to do for fun."

"Oh, all right."

He kissed the top of her head. "I rebuilt my flyer, by the way."

That woke her up. "Did you?"

"Probably still needs some work. Test flights, you know—fuel range, that sort of thing. I've got another one, too, more experimental; it's based on dragonfly flight mechanics."

She raised her head. " _Really?_ "

He grinned. "Sound like a date?"

"Sounds like a _honeymoon!_ "

He laughed, and she kissed him.

* * *

Two weeks later, Gil and Agatha sat out on a balcony with tea and opera glasses, watching von Zinzer direct the crew unloading the contents of Gil's labs from Castle Wulfenbach, which Father had sent on a couple of support ships. Just as the crew rolled the batwing flyer down the ramp toward a temporary hangar that the former prisoners had finished the day before, Tarvek stuck his head out the window of his lab behind Gil. "What the blazes is _that?_ " he asked, frowning down at the flyer.

Zoing immediately poured him a cuppa.

"Flying machine," Gil replied casually. "Still in development, but Agatha's already improved it a lot."

"Flattery will get you nowhere, dear," she teased.

Tarvek accepted his tea from Zoing without looking. "Where's the gasbag?"

"It doesn't need one," Gil answered. "At the speed it flies, the thrust from the propeller generates sufficient lift to keep it in the air."

"It actually worked tolerably well even before I redesigned the engine," Agatha admitted. "We wouldn't even have crashed if Gil hadn't been too distracted to watch where we were going."

Tarvek choked on his tea. " _Crashed?!_ "

"Noded," Zoing noted quickly.

"What—but—crashed?!"

"Into the Jäger generals' meeting room," Gil explained, rolling his eyes. "It broke the window. Nobody got hurt."

"Yes, and then you threw me out of the room," said Agatha.

"Because Father was coming and I didn't want him to know I'd been questioning you. He would have gotten entirely the wrong idea, which he did _anyway_ after he chased Othar into the lab and found you there."

"You could have explained that to me, you know."

"You married me anyway."

She shot him a sly look. "So I did."

"You are both certifiable," stated Tarvek.

Agatha turned to him, eyes too wide and innocent, and asked sweetly, "Don't you want to go for a test flight, Tarvek?"

Tarvek raised his chin. " _I_ am under house arrest, thank you."

"He's just jealous," said Gil.

"I am not. I wouldn't set foot in one of your death traps if you paid me."

"You're already _in_ one of my death traps."

" _My_ death trap, technically," Agatha corrected. "But I think the flyer might actually be safer."

"Thank you, Mistress!" the castle said brightly.

"Decadent, degenerate, and insane," Tarvek pronounced. "It's no wonder you married the Heterodyne, Gil—you fit right in."

"Coming from you, that's a compliment." Gil grinned and raised his teacup in salute.

"Aren't you supposed to insult our family now?" Violetta asked from somewhere behind Tarvek.

"Pass. I can't think of anything to say that isn't true."

"Oh, thank you _very_ much," Tarvek grumbled. "Want some tea, cousin?"

"No, thanks," Violetta replied. "I'm not thirsty. Ooh, what's that one?" she added, spotting the dragonflyer.

"Well, I haven't had a chance to test it since I made the most recent changes," Gil began.

Tarvek nearly choked again. "That contraption won't fly at all!"

"Science says it will."

"Then science can fly it!"

"Oh, honestly, Tarvek," Agatha interrupted, opera glasses trained on the courtyard, "anyone would think you were afraid of flying."

After a startled pause, Tarvek handed his teacup back to Zoing and slammed the window shut.

"Well played, _Schatzi_ ," Gil murmured over the rim of his own cup.

Agatha grinned. "He is _way_ too easy to tease."

"Who are we teasing?" Zeetha asked, bounding out through the door.

"Tarvek's afraid of flying," Agatha informed her, handing her the plate of biscuits.

"OOH! Are the flying machines here? I wanna try one!"

Gil snorted. "No."

"Why not? I've flown an airship."

"The steering on these is nothing like an airship. Besides, you'll try some crazy stunt and crash. Higgs would kill me. Then Father'd bring me back and kill me again."

"Hmph. Well, at least let me come on a test flight."

"Maybe one of the short flights," Agatha suggested. "Just around the valley, you know. You two haven't had much brother-sister time."

Gil looked at Zeetha warily.

Zeetha was almost pouting. "What about the long flights?"

Agatha blushed a little. "Ah, well, we'd been talking about being gone overnight..."

"And traveling incognito," Gil added hastily, feeling a bit of heat in his own cheeks. "You do stand out in a crowd, you know."

Zeetha flashed a sudden grin. "You two are adorable. All right, around the valley it is."

"Certifiable!" Tarvek yelled through the closed window.

Zeetha yelled back something in Skiff that Gil suspected was language unbecoming of a princess. Agatha spluttered, and Gil threw his head back and laughed.

* * *

By the time Gil and Agatha had rebuilt the main flyer's engine again and calculated the space requirements for takeoff and landing on the ground as opposed to launching from Castle Wulfenbach, Wooster had found a way to program the flyer's information into the Torchmen's recognition system, and von Zinzer had anticipated orders and overseen construction of an airstrip and hangar just outside of town. The short-range test flights were successful enough that Gil started using them as an excuse for picnics, occasionally with both Zeetha and Higgs along as well as Agatha for a double date. That phase of testing wrapped on Midsummer's Eve, and the hangar was well guarded and off limits to all guests who arrived the next day for the midsummer ball—except the baron, who arrived early and to whom Gil and Agatha proudly showed everything.

The baron's only question was, "You're not letting Zeetha fly this, are you?"

"Of course not," Gil replied. "At least not until I develop a better crash helmet."

The baron chuckled. "If she's as much like your mother as she seems, she wouldn't wear one even if you made it."

"Really?"

"In Skifander, one wears protective gear in the lab only when dealing with chemicals or fire, and never outside it. I've seen your mother go after Fafflenarg beasts without even taking her crown off. And as for clothing... well, let's just say that the state in which we found Agatha in Punch's shop was positively modest by Skifandrian standards."

Gil made a strangled noise.

Agatha felt herself blushing furiously. "Ah, speaking of my parents, Lilith should have lunch ready by now..."

The baron smiled wryly at her. "Of course. Forgive me."

It came as a great relief to both Gil and Agatha that Zeetha's outfit for the ball that night had an actual skirt, and her father-daughter waltz with the baron was downright demure. She more than made up for it later, though, by dragging Tarvek into a tango, much to the great amusement of everyone except Tarvek himself. (He got her back the next morning; she awoke to find her bedroom flooded with mimmoths and had to have the castle call Krosp to get her out.)

* * *

The serious long-range testing began after all the ball guests had gone home. Gil and Agatha started with day trips and gradually increased the range for weekend trips—to Vienna for the opera, to Rome for a symphony, to Berlin for an art exhibit, to Zurich, to Venice, to Moscow, to Paris. Other weekends they went to smaller villages off the beaten path, sometimes for the markets and sometimes for the scenery. Even after they'd honed the design to a point where they were both satisfied, they kept finding excuses to get away. And always they gave an assumed name wherever they stayed. Since the flyer bore neither the Wulfenbach nor the Heterodyne sigil, it didn't give anyone any clues as to who they were.

It was December before someone finally figured out that the "flying sparks" were in fact the Heterodynes. And suddenly they found themselves besieged... by requests, and sometimes demands, for flyers. Apparently everyone who was anyone wanted a flying machine, and most of them wanted it before the holidays.

"What'll we _do?_ " Gil groaned, clutching his head as Wooster brought in yet another mail sack. "I can't build that many flyers that fast, even if Punch _and_ von Zinzer help me!"

Van, whom Agatha had called in to consult, raised an eyebrow. "Have you forgotten where you are, milord? Give us the plans, and we can have the old kraken works repurposed and turning out flying machines by the end of the week."

Gil blinked at him. "Seriously?"

Punch put a hand on Gil's shoulder. "It's true. They're hard workers, and they'll jump at the chance to take on a project like this for the master and mistress. 'Made in Mechanicsburg' still means quality."

"Yes, but it used to mean death and destruction as well," Judy noted from where she and Agatha were sorting letters. "We'll need an airtight warranty so no one will take an accidental crash to be a declaration of war."

Gil's eyes narrowed as he thought. Then he looked up at Wooster. "Sounds like a job for Sturmvoraus, wouldn't you say?"

Wooster smiled. "You know, I believe it does, sir."

And so it was settled. Agatha's secretaries took charge of the correspondence, and Van had the factory staffed by suppertime. Tarvek presented the draft warranty at breakfast, which Agatha read and approved; then she spent the morning building a signing machine to deal with the printed copies that would be arriving by nightfall. Punch helped Gil work out a price schedule, and Judy went down to the factory to give advice on fabrics and color schemes. And Gil spent the rest of the week training pilots to deliver the flyers to the customers and, if requested, to train the customers in turn. The earliest orders were from sparks who could pick up the basics on their own, but Gil knew the Fifty Families would want training. And Mechanicsburgers, while not sparks themselves, were fast learners and good teachers.

"To think we used to rob graves for the masters," one of the pilots said after a session.

Gil clapped him on the shoulder and grinned. "This is more lucrative, trust me. And besides, you'll get hazard pay."

As Van had promised, the first flyers rolled out at week's end. And once the money started rolling in, Mechanicsburg found itself having a very merry Christmas indeed.

* * *

The airship yards started sending complaints in February. Agatha drafted a form letter explaining that the price for a flyer really wasn't comparable to that of an airship and that the flyer lacked an airship's flexibility for passenger service and military use. Both points were true, and the airship yards' business didn't suffer as much as feared in the short term, so that storm blew over fairly quickly.

The concerned letter from Abbot Gerät of St. Szpac took more consideration. Gil's answer was to offer to donate a small fleet for the Corbettites to use for aerial surveying and for search and rescue. Father Gerät ordered twenty, and Brother Matthias, the spark engineer who arrived to inspect them before delivery, thoroughly embarrassed his companion, Brother Ulm, by waxing poetic about the design and then running into the cathedral to thank God for the Heterodynes, dancing and singing hymns about science all the way.

"Good job we didn't let him drink Agatha's coffee, eh?" Gil murmured to Van.

Van, who'd actually volunteered for that taste test and hadn't stopped rhapsodizing for hours afterward, nodded grimly.

Not a few requests arrived for flyers with gun turrets added, some of which included drawings that were clearly done by sparks who had no understanding of the flyer's design. Tarvek drafted that form letter, with Agatha's approval; it stated in no uncertain terms that the flyers were pleasure craft only and that adding weapons to them would be a clear breach of the Baron's Peace. Gil then sent a copy of the letter, along with names and addresses, to Father, who not only approved but sent a few reminders of his own to the fools in question. (Some of them were then discovered to be harboring Geisterdamen and/or hive engines, so that turned out well for everybody.)

By the time the first warranty claim for a crash arrived, Gil had developed a satisfactory helmet and was already planning the market release with Van's help. Father took charge of the crash investigation and determined that it was caused by the owner's tinkering, so Mechanicsburg Aeronautics was clearly not liable. The same held true for a string of crashes caused by weather and pilot error throughout the spring, and soon the helmets were flying off the shelves.

Othar Tryggvassen crashed his flyer five times before demanding his money back. Agatha offered to train Sanaa as his co-pilot instead. He decided to drop his claim and go back to travelling by train.

Gil and Agatha's first anniversary coincided with the production of the one-thousandth Mechanicsburg Flyer, which was all the more cause for celebration. In the middle of it all, while Gil was busy shaking hands, Zeetha sneaked out to the airstrip and got into his original model. Before von Zinzer could stop her, she took off and circled the city twice before putting on a spectacular show of dips, loops, spins, and rolls that had Gil fighting to breathe, Agatha biting her nails, and Father shaking his head. But the rest of Mechanicsburg cheered wildly, and not only did Zeetha not crash into the mountains, she landed safely on the airstrip and started back to town on foot, laughing and waving to the enthusiastic crowd.

 _Then_ the engine exploded.

"Well, we know the limits of the design now," Father deadpanned as the Jägers carried Zeetha back into town on their shoulders.

Gil buried his face in his hands. "I'm going to kill her."

Agatha took a deep breath. "It... does suggest possibilities for a new design we could market to circus acts. A more robust engine, sturdier fixed wings..."

"We could call it the Warrior Princess!" Van suggested.

Gil dropped his hands. "I've created a monster."

Father chuckled. "Well, you _are_ a Heterodyne now, son. It comes with the territory."

That finally got Gil to laugh.

Later that night, however, when the feasting had finally wound down enough that Gil could take Agatha back to the castle for some private frolicking, he asked as they walked into the bedroom, "Were you serious about the circus flyer?"

"Mm, mostly," she replied, sounding tired. "But I think we should have the Jägers do the testing for that one. If it's Jäger-proof, it might even stand up to Othar."

He chuckled. "Should we work on that before or after the dragonflyer?"

"Either way... I don't think I'll be up to being a test pilot for a while."

"You... you don't? Is that because of Zeetha, or..."

For answer, she pulled off her blouse and turned to let him see that the bottom half of her corset busk was unfastened to leave room for a very slight bulge.

"... Agatha?" He walked up to her, staring at her stomach.

She took his hand and pressed it to her skin, let him feel that... yes, all the signs were there. "Lilith says I should show in another month or two," she said with a small smile when he dragged his eyes up to meet hers again. "I didn't want to tell you until we were sure. Happy anniversary, Gil."

He kissed her and realized he didn't need to be in the air for his heart to fly.


End file.
